Factory Five Racing Forum banner
1 - 17 of 17 Posts

·
Junior Charter Member
Joined
·
1,164 Posts
Discussion Starter · #1 ·
Im Considering rebuilding my fox 8.0 axle as ive already bought 3.55 gears, bearings, seals and Girdle Ive never domne a fox but wouldnt imagine its much different from any other ive built before
Couple of questions is there a collapsable spacer in the pinion brg and is there anything i should know when adjusting checking pe load etc
my problem is time and patience for this so im on the fence but also running out of DOSH (money$$$)

Thanx in advance
jimmy O
 

·
Senior Charter Member
Joined
·
692 Posts
It's not too bad. You'll need a good indicator and probably an impact gun to collapse the collar. Use the shim from the original gear set, as it will more than likely be the same.

The hardest part is getting the spacer to start collapsing.
 

·
Senior Member
Joined
·
1,752 Posts
Jimmy,
I'm in the process of doing mine now. I would strongly suggest you get a copy of a DVD by Kennith Collins. He's a certified Ford tech and he walks you through a complete rebuild of the 8.8. Search Ebay for badshoe productions. If you're going to do it yourself it's money well spent.

To answer your other questions, yes there is a crush sleeve under the pinion nut that requires 200 to 400 ft/lbs to torque down to get the proper preload on the pinion bearings. You'll need an inch pound torque wrench to check it with. Also if you haven't disassembled the rear yet, wait until you get the DVD. There are some things that are helpfull to check prior to disassembly.

Good luck

Rich
 

·
Junior Charter Member
Joined
·
5,413 Posts
Hey Rich I did a searhc on Badshoe productions got no hits. Are you sure about this
Thanks
Chris
 

·
Senior Member
Joined
·
1,913 Posts
I'm well into the process of doing the same, mainly because of silly $ quotes I received for outsourcing the job.

With all due respect to the previous poster, everything that I have read says do NOT use an impact wrench to tighten the pinion nut (cruching the crush spacer) as you have to "sneak up" on the right amount of crush using an accurate in-lb wrench.

I haven't installed the new pinion yet, but breaking it down and rebuilding the posi was pretty easy if smelly (friction modifier.....).

Googling will get you far - here's some links that have helped me get where I am:
http://www.corral.net/tech/drivetrain/gears.html
http://www.cartechbooks.com/vstore/showdetl.cfm?DID=6&Product_ID=2557&CATID=21

I am planning on using the "ugly" pinion depth technique from the second link. I needed to buy a stouter 2 arm puller, a 12" caliper/depth gauge, and I made a "******* pinion wrench" using bar stock for tightening/loosening the pinion nut. I still need to make/buy/borrow an in-lb wrench that can provide accurate readings from 12-30 in-lbs, this seems to be pretty critical for success.

Feel free to PM me, I can send photos or share experience to date regarding my first diff rebuild in 20+ years!!
cheers,
timm

PS - I chose to replace ALL bearings while I was in there (donor had 90K), favorite trick so far was using a 6' steel pipe to drive out the axle bearings instead of a puller... took 2 minutes and saved me fabricating something to let my slide hammer hold onto the old axle bearings!
 

·
Senior Member
Joined
·
2,746 Posts
I did exactly what you are thinking about, with a set of used 3.55's that I bought here on the forum. Here is a link to the document I used for help and direction.

http://www.corral.net/tech/drivetrain/gears.html


I did not need much in the way of special tools, I have all the normal hand tools. I have a dial indicator, I fabbed a bracket to go across the pumpkin at the back to check pinion depth. The job was not that hard. When I was done the pattern looked like this;



I do have air tools including a 1/2" impact, which was used to get the pinon assembly apart. I didn't use it to put it together, that was done a teeny-tiny step at a time with much checking of torque betweet twists. You don't want to crush the crush washer too far, you'd just have to start over. I also replaced all the bearings and seals, as did Tim in the post above.

I'd be happy to reply to any questions you might have, although I am by no means an expert.

Of course, my car is still only about half-built, so it remains to be seen whether or not, my rear end re-build is correct or not, for what it's worth.

Chris.
 

·
FFCobra Fanatic
Joined
·
12,975 Posts
Also do not recommend useing an impact wrench to tighten the crush sleeve. The pupose of this sleeve is to put the correct amount of pre load on the pinion bearing. It needs to be checked and set with a "dail type inch pound tq. wrench. clicker type will not work as well here.
Couple of things to help when setting up your gears. Save the old pinion bearing and use a dremmel tool or similar to open up the id of the bearing. You want it to become a slip fit instead of a press fit on the pinion shaft. Doing this lets you install and remove the bearing as your trying different shims when setting pinion ht. It is possible to not use a pinion depth guage and use the compound to read tooth contact instead. Save old crush bearing and use it along with old slip fit bearing when checking. Only tighten the pinion nut(old nut used) till no play is felt in bearing,or only tighten nut till up against old sleeve. I put lapping compound on threads of old pinion nut and ran it on and off the threads of an old pinion gear. This made the nut non locking and threaded on and off the shaft without resistance. Just makes assembly and disassembly easyer not having to hold flange while tq.ing nut. Regular fine thread nut will work if you find one. Start with original shims under pinion gear,set back lash and use compound to check pattern. Make shim changes based on this. Get a manual or video or some sort of literature before rebuilding. Give it a try. Get stuck ask questions here.
 

·
Junior Charter Member
Joined
·
1,164 Posts
Discussion Starter · #10 ·
Thanx guys im definitley going to do the rebuild myself i appreciate all the advice & any pics info please feel free to e,mail me the more info the better

jimmy O
 

·
iBuild
Joined
·
5,824 Posts
Another in favor of the Bad Shoe Video, and not using an impact wrench. I rebuilt the 8.8 for the IRS, really pretty straight forward.

I am 95% sure the my pinion pattern is really good, but having not done it before, there is that slight is it right feeling. I have seen a few guys post photos of the wear pattern to get some board approval on it, and highly recommend it for that added piece of mind.

Also, on the crush sleeve, I drilled two holes in a small peice of aluminum and ran two of the pinion flange bolts through it. A large screwdriver handle under the aluminum between the bolts, with the other end locked into a vice. With everything locked down and the housing not able to move, the crush sleeve wasn't too bad, used a 3ft extension on a 1/2 socket.

As others have said, you need to creep up on it. Once you get close, you will want to check the preload far more often then you think needed. (I killed my first collar with what seemed like no more then an 1/8 turn from where it was prior.)

_Scott
 

·
Senior Member
Joined
·
2,746 Posts
One more thing I would add to this is that several people said during my re-build that if I had Ford brand gears the re-build would come off correctly the first time. As it happened, I had Ford gears, (dumb luck, not good planning) and was able to put everything together with the original shims, first time, no second fitting needed. For what it's worth, several posted that they had gears made by someone other that Ford and that they had had to re- fit several times with different shim thicknesses....


Chris.
 

·
Blue Oval Scribe
Joined
·
9,177 Posts
I didn't see it mentioned here, but many builders are using a solid spacer now instead of a crush sleeve. As you have read, just a little more "turn" on the pinion nut can ruin the crush sleeve, well, racers were finding their gears trashed because high power to the rear wheels was pushing the pinion gear and crushing the sleeve further, creating slack...

The 8.8 that Drivetrain Specialists built for our project does not have a crush sleeve, but instead one of these solid spacers...

The DVD mentioned above (the latest version) supposedly has a segment on the solid spacer vs. the crush sleeve.

Mark
 

·
Senior Member
Joined
·
1,913 Posts
The same "badshoe" production is available for rental from "Smartflix" at http://smartflix.com/index.php?main_page=product_info&products_id=3742

Looks like it is $25 to rent both DVDs, I think I will try them out.

Has anyone here seen a used gear set where the stamping #s are legible? I've looked at 2 so far, and the supposed pinion depth #s and gearset IDs are all but impossible to read completely...

MMMmmmmmm - friction modifier. I'll be sleeping in the guest room until the smell washes off!!
timm

PS - my donor diff had about 2 in-lbs of preload on it, wonder if that was related to the pinion snout leak.....
 

·
FFCobra Fanatic
Joined
·
12,975 Posts
Tim, not all gears have the pinion ht. numbers stamped or engraved on them. Even my new ford gears had no marking other then ratio. Best suggestion is to try the original shims first. Many times the originals will be correct. Gear pattern checks useing gear compound will let you see if more or less hieght is needed. Just be sure to set proper back lash (.008-.012") before taking a reading.
Also agree with useing Ford brand gears. After useing brand name and after market gears the Ford parts always go together better.
Not sure but saw an episode on "Myth Busters" about removing the smell caused by getting sprayed by a skunk. Wonder if any of the remedys work for removing friction modifyer smell? :D
 

·
Senior Member
Joined
·
5,559 Posts
Mustang Man,

Brought up a good point with regard to the pinion bushing/spacer. I build dozens of these, and every one of them uses a solid spacer kit for 2 reasons. 1. the crush sleeve is very fickle as has been discussed above, and 2. the solid spacer will not change length regardles of the torque a particular combo can put to the pavement. It's really cheap insurance if you plan to have big hp/torque numbers at some point. The other good thing is that once it is properly shimmed (a fairly time-consumming process), you can disassemble the pinion if you ever have a leak, or some other reason, without losing your setup. With a crush sleeve the game is over as soon as you untorque the nut!

Brian
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top